Separable brushes



1960 B. 18 THONBO ETAL 2,963,729

SEPARABLE BRUSHES Filed April 21, 1958 FIG. 2

FIG.4

Inventors BENDT IB THONBO GUNNAR THONBO FIG. 3

SEPARABLE BRUSHES Bendt Ib Thonbo and Giinnar Thonbo, Copenhagen, Denmark, assignors t A/S Gubin, Herlev, Denmark, a company of Denmark Filed Apr. 21, 1958, Ser. No. 729,821

1 'Claim. Cl. 15-176) This invention relates to improvements in brushes of the separable type and particularly to an improved brush structure of this class in which the brush part is securely locked to the handle during use and prevented from sliding thereon.

Prior brushes of the class considered herein are exemplified by the brush disclosed in United States Patent No. 2,795,807 dated June 18, 1957, in which an elongated base member having an arcuate transversely curved supporting surface embodies longitudinal side grooves on the terminus of an arcuate surface of greater than 180 degrees extent. The resilient bristle member including a sheet portion and beading along the edges of the sheet portion is slidable onto the arcuate surface for insertion of the beaded portion into the grooves. The sheet portion looseiy extends about the arcuate surface on the base member to provide for a cushioning or resilient effect of the sheet member when mounted on the base member. The sheet member is not therefore tensioned and is held solely on the base member by friction of the beaded portions in the longitudinal grooves of the base member. During usage the beaded portions tend to loosen in the grooves. Ordinarily therefore, unless great care is taken in the production of such prior art articles or in any case after some continued usage of such articles of the prior art, the beaded portions may slide too freely within the grooves and permit the bristle member to come free of the base member during use.

It is the main object of the invention to overcome the particular disadvantages of prior constructions of brushes of the class defined herein.

it is another object of the invention to provide a separable brush structure in which the bristle member sheet is positively tensioned over the base member arcuate surface and is retained in locked position thereon by reason of sheet tensioning and in which end wall portions are provided in the base member for restraining the sheet against endwise movement on the base member during use.

Other objects of the invention will be appreciated by the study of the following specification taken in conjunction With the accompanying drawings.

In the drawings:

Figure 1 is a perspective view of an improved separable brush structure according to the invention.

Figure 2 is a partial sectional view on the line 2-2 of Figure 1.

Figure 3 is a. sectional view on the line 33 of Figure 1.

Figure 4 is an end view of the bristle element of this invention in its normal unflexed position.

Figure 5 is a partial perspective view illustrating the manner of inserting the base member of the handle portion of the brush of the invention into the bristle member.

In the drawings the improved separable brush construction of the invention comprises a handle portion including a base member 11 and a handle part 12. The base member 11 is of elongated form having a transverseatent 1y convex arcuate contour or surface 13 of substantially degrees of arcuate extent as shown in Figure 3. Two parallel spaced apart longitudinally extending grooves 14 are located inwardly of the lateral arcuate extent, that is the side longitudinal edges 15, of the base member and extend in the base member toward the arcuate surface thereof at an angle A of about 45 degrees from a geometric radius 16 extending to the ends 17 of the arcuate supporting surface 13.

Clamping surfaces 18 extend on the base member from each locking groove 14 thereof outwardly geometrically to intersect the arc of the supporting surface at an included angle B of about 45 degrees and substantially at the ends of said are. F

A bristle member 19 embodies a substantially normally fiat resilient tensionable supporting sheet 20 preferably formed of polyethylene of a size, that is, of a length .and width, adapted to overlie or cover the arcuate surface 13 of the base member 11. The supporting sheet 20 has parallel longitudinally extending side terminal edges 21 substantially from which the longitudinal clamping flanges 22 extend inwardly at an included angle of about 45 degrees thereby corresponding to the angle B. Clamping flange 22 in each case is adapted to engage the clamping surfaces 18 of the base member.

A longitudinally extending locking flange 23 of predetermined length is provided on each clamping flange 22 and defines an inward terminus therefor extending at an angle of about 90 degrees therefrom toward the sheet 20. The base member as seen in Figure 1 embodies end wall portions 24 and 25 defining the longitudinal extent of the locking grooves 14 to a dimension accommodating the locking flange 23. Accordingly the locking grooves of the base member are of a predetermined length adapted to accommodate the locking flanges of the bristle member and to restrain the latter from longitudinal sliding motion therein.

In use the base member, as indicated in Figure 5 in which the perspective view thereof looks downwardly toward the outer end 26 of the base member the bristle member sheet 20, is caused to slide over the base member due to the flexible nature of the clamping and locking flanges 22 and 23 thereof riding over the end wall portions 24. When the support sheet 20 of the bristle member arrives in the position indicated in Figure 2 relative to the base member 11 the locking flanges 23 will seat within the locking grooves 14. The tensioning of the sheet 20 necessary to enable the locking function to be accomplished by reason of the geometry, that is the relative position of the grooves and arcuate supporting surface, is accomplished by providing an air cushion recess 27 within the arcuate surface 13 to permit flexing of the sheet 20 over a flexing portion 28 thereof illustrated in Figure 2. It will be realized therefore that in the assembly positions illustrated in Figure 5, the sheet 20 when moved to the region of the recess 27 enables the locking flanges 23 to be fully inserted within the locking grooves 14 while continuing sliding assembly. In final assembly both ends 29 and 30 of the sheet 20 are fully supported by full arcuate surfaces 31 and 32 of the base member while a cushioning or flange portion 28 is partially unsupported therebetween except over the arcuate edge portions 33 extending longitudinally and defining the side limits of the cushioning recess 27.

It is intended that the present disclosure should not be considered in any limiting sense other than that of the following claim having regard to the art.

What we claim as our invention is:

A brush comprising in combination: an elongated base member; a brush element supporting surface on said base member of transversely convex arcuate contour of substantially 90 degrees of arcuate extent; two parallel spaced apart longitudinally extending locking grooves of predetermined length in said base member located inwardly of the lateral arcuate extent of said supporting surface and extending in said base member toward thearcuate surface thereof substantially at an angle of about 45 degrees, respectively, from a geometric radius extending to the respective end of the arc of said supporting surface; a-clamping surface on said base member extending from each locking groove thereof outwardly geometrically to intersect the are of said surface at an included angle of about 45 degrees; a bristle member including a substantially normally flat resilient tensionable supporting sheet adapted to cover said arcuate surface of said base member and having parallel longitudinally extending side terminal edges; a longitudinal clamping flange extending inwardly from each side edge of said sheet at an included angle of about 45 degrees and adapted to engage a clamping surface of said base member; a longitudinally extending locking flange of substantially said predetermined length on each clamping flange defining an inward terminus therefor and extending at an angle of about 90 degrees therefrom towards said sheet and insertable into said locking grooves of said base member to tensionably clamp said sheet on the latter and restraining said sheet against longitudinal movement on said base member; an air cushion recess in the supporting surface of said base member extending longitudinally thereof a distance less than the length of said supporting sheet when clamped thereon and adapted for resilient flexing of said sheet thereinto; and integral rigid end wall portions on said base member at each end of each said locking groove defining thelongitudinal extent of each locking groove.

References Cited in the file of this patent UNITED STATESPATENTS 2,795,807 Salvy June 18, 1957 FOREIGN PATENTS 480,845 Great Britain ...ta. Mar. 1, 1938 1 ,072,436 .France a Mar. 17, 1954 1,139,207 France Feb. 11, 1957 a. MA M... 

